Folding landing gear



E. H. TOWLE FOLDING LANDING GEAR Filed Sept. 24, 1919 2 Sheets-Sheet 1Jan. 1925- 11,523,675

E. H. TOWLE FOLDING LANDING GEAR Filed Sept. 24 1919 2 Shoots-Sheet 2Patented Jan. 20, 1925.

PATENT- OFFICE.

ELLINGWOOD H. TOWLE, 0F LARGHMONT, NEW YORK.

FOLDING LANDING GEAR.

Application filed September 24, 1919. Serial No. 326,003.

T 0 all whom it may concern:

Be it known that I, ELLINGWOOD TOWLE, a citizen of the United States,residing at Larchmont, in the county of Westchester and State of NewYork, have invented certain new and useful Improvements in FoldingLanding Gears, of which the following is a specification.

This invention relates to a folding landing gear for airplanes.

The primary purpose of a folding landing gear is, of course, to decreasethe head resistance of 'the airplane. To this end 1t 15 an object of myinvention to design a land ing gear which folds .up along axessubstantially parallel to the longltudlnal axis of the fuselage, and inwhich the wheels, when folded, lie substantially horizontall along thebottom of the fuselage.

. In landing gear folding on a transversely extending axis, the shock oflanding tends to fold up the gear. In a landing gear pivoted on alongitudinally extending axis, however, the shock of landing istransmitted directly to the axis and when the wheels are unfolded haspractically no tendency tofold up the landing gear.

It is a further object of my invention to design a landing gear in whichthe pair of arms that function to raise and lower one landing gear frameare enclosed between or straddled by the pair of arms that operate theother landing gear frame. Such a construction permits the folding of thegear. The folding, however, of the two wheels is intended to besuccessive rather than simultaneous.

It is a further object of my invention to provide a. cover to cover upthe landing gear when in its folded position sothat the fuselagepresents a smooth exterior to minimize air resistance.

Other objects and advantages will appear as the description proceeds.

In the drawings illustrating several embodiments of my invention,

Fig. 1 is a side View, partly in section, of an airplane fuselageshowing certain parts of my landing gear.

Fig. 2 is a section on the line 2'2 of Fig. 1, looking in the directionof the arrows.

Fig. 3 is a section on the line 33 of Fig. 1, looking in the directionof the arrows.

Fig. 4 is a detached perspective view of the landing gear frame.

Fig. 5 is a view similar to Fig. 2 of a modification.

Figs. 6. 7 and 8 are a, front View, side view, and sectional planrespectively of one landing wheel and associated parts, in which thelanding gear is made out of piping. Fig. 8 is taken on the line 8-8 ofFig. 7.

Fig. 9 is a view similar to Fig. 2 of another modification.

Fig. 10 is an enlarged view of certain parts shown in Fig. 9.

Fig. 11 is a view of a joint used in the modification shown in Figs. 9and 10.

Referring now to the drawings, the airplane fuselage, indicated at 1,carries a pair of longitudinally extending beams 2 and 3, to which beamsare attached the bearing plates 4. The landing gear frame comprisesstandards 5 connected by the horizontally extending portion 6 and bracedby the diagonal braces 7. One of these frames is pivoted to each of thebeams 2 and 3 on pivots 8 carried by the bearing plates 4. It will beapparent that the' frame may be folded up along a longitudinal axis. Thebottom of the fuselage is suitably cut out, as indicated at 9, to allowthe frame to fold upwardly into the same.

Each frame has mounted therein a landing wheel 10.

Rotatably mounted in suitable supports 11 is a threaded shaft 12provided with a gear 13 meshing with a worm 14 carried by a shaft 15pivoted in bearings 16, which shaft is manually rotatable by means ofsprocket wheels 17 and 18 and chain 19.

Two of these threaded shafts are provided for each of the landing gearframes. Engaging with each of the shafts 12 by means of a threadedcollar 20 is the operating arm 21, which is pivoted to the folding frameat the point 22. i

It will be apparent that rotation of the shaft 12 will lift the collars20 and pair of arms 21 and draw up the landing gear frame.

The pair of arms 21, which are attached to collars 20 at their upperends and to the other landing gear frame at their lower ends, arearranged outside of the arms 21 to straddle the same, as shown in Fig.4. This feature is important, and permits the sucshown in dotted lines.

lowering arms, serve to brace the wheels fuselage is indicated at 1.against the shock of landing. It should lng frames 50 and 51 are pivotedat 52 and .also be noted that even if the wheels are 53 to suitablestruts 54 and 55, positioned cessive foldin'g up of the two frameswithout Similar operating means are provided for interference.

arms 21 is, of course. folded up first. arms for that wheel on the otherside, corre- The other landing gear is drawn up by sponding to 39 and42, are on the outside means similar to the means just described, orstraddle the arms 39 and 42. It should the shaft 15 and manuallyoperating means also be understood that arms 39,42, 45, etc.,

. simply being duplicated on the other side of are duplicated at thefront and rear of the landing gear 31, and similarly the come thefuselage.

spending parts attached to the frame 32.

As shown in Fig. 2, theleft-hand wheel and frame, which are drawn up bythe arms 21 that are positioned on the inside, are shows the mo'dlficaton of Fig. 5 constructed drawn up first. After the wheel is in th'e outof tubing, and corresponding referencedotted position shown in Fig.2,then the characters indicate corresponding parts. wheel on the otherside is drawn up to its The landing wheel 10 is. supported in a positionso that the two are superposed. fork 47. i

It should be noted that the operating arms The modlficati-on shown inFigs. 9 and 10 21 in addition tofunctioning as raising and will now bedescribed. In these figures the The wheel carrynot extended to theirextreme position, by laterally of the fuselage, sothatthe pivot virtueof the rigid connection that would points are farther apart than shownin the be afforded by the arms '21 and threaded other modifications. Theoperating mechashafts 12, the shock of-landing will be fairly nism ofthese figures is precisely similar to well taken up in spite of this.that shown in Fig. 5and need not be repeated A door 23 sliding on guides24 and ophere, the corresponding parts in the two figerated by a pair ofcables 25 attached'at ures being indicated by corresponding ref- 26 and27 slides back and forth to cover erence characters. The increasedspacing the landing gear frames when folded up, between the pivot points52 and 53 permits as shown in the dotted position in Fig. 2. the wheels10 to assume the dotted position The cables 25 may be operated by amanually shown in Fig. 9, where they lie against the operated drum 28. 1bottom of the fuselage without overlapping. Referring to Fig. 4, it willbe noted that Sliding doors similar to the door 23, the inner pair. ofarms 21 are offset, as indishown in Fig. 1, may be used with any of thecated at 21. This is topermit proper enmodifications shown. gagement ofthese arms with the appropriate In case the joint 41, Fig. 9, is made.out of pair of shafts,12, which must be positioned piping, the jointshown in Fig. 11 may be as shown to avoid interference with theleftused. Arm 42 may be provided with a hand frame 5 of Fig. 4.flattened portion 42 and arm 39 with a slot Referring now to themodification shown 39 to permit the arm 39 to assume the in Fig. 5, thewheels 10 are carried by frames dotted position shown in Fig. 11. 31 and32 pivoted at 33 and 34 on axes ex- While I have shown a separate manualtending longitudinally of the fuselage, as in means for drawing up eachlanding wheel Fig. 1. The means for drawing up these frame, it should beunderstood that a single frames, however, is some-what different. Inmanual means could readily be provided to order to draw up the left-handframe 31, two perform this function, it being so designed threadedshafts 35, only one of which is that it would draw up the two landingwheel shown in Fig. 5, are provided, positioned on frames successively,the frame to which is the same side of the fuselage as the frame 31.attached the inner pair of operating arms These threaded shafts arejournaled in suitbeing the one to be drawn 'up first. able bearings andare rotated from the han- While I have illustrated certain embodidle 36by means for the chain 37 and gears 38. ments of my invention, it shouldbe under The frame operated by the the wheel on the other side; theoperating 7 The construction shown in Figs. 6, 7 and 8 I An arm 39,pivoted at 40 to the frame 31, stood that it may be carried out in otherI is pivoted at 41 to another arm 42 pivoted ways, and that accordinglythe disclosure he at 43 to the bracket 44 carried by a beam 3 consideredin an illustrative sense only.

of the fuselage. An operating arm 45 is I claim as my invention:

pivoted at the already described point 41 p 1. In a folding landinggear, a pair of to arms 39 and 42. At its upper end this frames pivotedto the fuselage, a wheel cararm 45 is forked and engages with the riedby each frame, a pair of operating arms threaded collar 46 that ismounted on the connected to each of said frames, so that threaded shaft35. It will be apparent that one pair of said operating arms is posiwhenthe shaft 35 is rotated, the left-hand tioned between the other-pair,and means to wheel 10 will be drawn up to the position actuate theoperating arms.

2. In a folding landing gear, a pair of frames, each pivoted on an axisextending longitudinally of the fuselage, operating arms connected toeach 'of said frames to draw them up, threaded shafts, means operativelyconnecting said operating arms to said threaded shafts, and means torotate said threaded shafts.

3. The combination as claimed in claim 1, in combination with means tocover the landing gear when folded.

4- In a folding landing gear, a pair of frames, each pivoted on an axisextending longitudinally of the fuselage, operating arms connected toeach of said frames to draw them up, threaded shafts, means operativelyconnecting said operated arms to said threaded shafts, and means torotate the said threaded shafts in combination with means to cover thelanding gear when folded.

5. A retractible landing gear comprising a retracting worm, a threadedsleeve upon the worm, a substantially rigid member carrying at its lowerend a landing wheel, connection between said member and the sleeve, andmeans for rotating the worm;

6. In a folding landing gear for aircraft, a pair of frames, eachpivoted on an axis extending longitudinally of the fuselage of saidaircraft, operating arms connected to each of said frames to draw themup or to extend them, threaded shafts, means operatively connecting saidoperating arms to said threaded shaft, means to rotate said threadedshafts, said operating arms and said frames being adapted to take allof. the shock of the landing of the aircraft when the landing gear is inan extended position.

7. In a folding landing gear for aircraft, a pair of frames, eachpivoted on an axis extending longitudinally of the fuselage of saidaircraft, operating arms connected to each of said frames to draw themup or to extend them, threaded shafts, means operatively connecting saidoperating arms to said threaded shaft, means to rotate said threadedshafts, said landing gear being so devised that none of the shock oflanding of the aircraft is transmitted to the threaded shaft or to theconnecting means when said landing gear is in extended position.

8. A retractible landing gear comprising a retracting worm, a threadedsleeve upon said worm, a substantially rigid member carrying at itslower end a landing wheel, an operating arm adapted to extend or retractsaid landing wheel, a connection between said operating arm and saidsleeve, and means'for rotating said worm, said operating arm and saidrigid member being adapted to receive the entire shock incident to thelanding of the aircraft.

9.,A retractible landing gear comprising a retracting worm, a threadedsleeve upon said worm, a substantially rigid member carrying at itslower end a landing wheel, an operating arm adapted to extend or retractsaid landing wheel, a connection between said operating arm and saidsleeve, and means for.rotating said worm, said operating arm and saidrigid member being so designed that none of the-shock of the landing ofthe aircraft is transmitted to said connecting means or said retractingworm.

10. In combination, in a retractible landing gear for aircraft, aretracting worm, a threaded sleeve upon said worm, a substantially rigidmember carrying at its lower end a landing wheel, operating means connected to and adapted to retract or extend 11 said rigid carryingmember, connecting means operatively connecting said threaded sleeve andsaid operating means for the purpose described, said rigid member andsaid operating means being adapted to receive all of the shock incidentto landing of said aircraft.

11. In combination, in a retractible landing gear for aircraft, aretracting worm, a

threaded sleeve upon said worm, a substantially rigid member carrying atits lower end a landing wheel, operating means con nected to and adaptedto retract or extend said rigid carrying member, connecting meansoperatively connecting said threaded sleeve and said operating means forthe purpose described, said rigid member and said operating means beingadapted to take all of the shock incident to the landing of saidaircraft, none of said shock being transmitted to the connecting meansor to said sleeve.

12. In combination, in a retractible landing gear for aircraft, aretracting worm, a threaded sleeve upon said worm, a substan tiallyrigid member carrying at its lower end a landing wheel, a hinged shaftconnected to and adapted to retract or extend said rigid carryingmember, a connecting shaft operatively connecting said threaded sleeveand said hinged shaft at its hinged portion to form a toggle joint, thetwo portions of said hinged shaft being adapted to form a straight linewhen the landing gear is in extended position, said hinged shaft andsaid rigid member being adapted to re ceive all of the shock incident tothe landing of the aircraft.

In testimony whereof I afiix my signature.

ELLINGWOOD H; TOWLE.

